Sedimentation in the Riparian zone of an incising river

This paper focuses on one aspect of riparian zone change associated with channel incision. It presents information on sedimentation within the riparian zone of the River Garonne, France, derived from both historical and contemporary sources. The riparian zone investigated is morphologically complex, containing a remant island and cut-off channel. Information drawn from historical and contemporary sources permits the reconstruction of channel planform and cross-profile change as well as an assessment of changes in riparian zone sedimentation rates and patterns. Very significant changes are identified over the last 50 years: A change from a multiple thread to single thread channel planform; high rates of riparian zone sedimentation of the order of 0.5 to 2.5 cm a1; clear spatial patterns in over-bank sedimentation, reflecting topographic and vegetational variations and flood event magnitude; and a reduction in morphological and vegetational diversity through the period, which is expected to continue as the zone is transformed into an increasingly homogeneous sediment sink. Copyright (c) 2001 John Wiley & Sons, Ltd.